Acoustical panel

ABSTRACT

A method of making an acoustical panel includes providing a fiberglass substrate, applying an adhesive to the substrate, and applying a facing to the adhesive. The resulting acoustical panel laminate has a smooth exterior face. Further, an acoustical panel includes a rigid fiberglass board, an adhesive layer, and a fiberglass mat coupled to the fiberglass board by the adhesive layer.

FIELD OF THE INVENTION

[0001] The present invention relates to acoustical panel insulation. More specifically, the present invention relates to a process of making an acoustical panel insulation laminate.

BACKGROUND OF THE INVENTION

[0002] Acoustical panel insulation is used in a wide variety of applications. Examples include ceiling tiles, modular office furniture, automotive vehicle headliners, and airplane interiors. Acoustical panel insulation can be comprised of a substrate and an exterior layer. The material used for the substrate often includes imperfections such as divots, pits, holes, etc. due to its material, particularly in the case of a rigid fiberglass substrate. The exterior layer can be attached to the substrate by fusing the two layers together during the manufacturing process to create the laminate.

[0003] Two primary considerations in the design of acoustical panel insulation include the degree of sound absorption and the exterior appearance of the resultant product. The degree of sound absorption is related to the acoustical impedance of the materials used in constructing the acoustical panel insulation, which in turn is a factor of the material air flow resistance, material density, material thickness, and the frequency of the sound. The laminate structure of conventional acoustical panel insulation optimizes the sound absorption of the insulation while minimizing cost, mass, and thickness of the end product.

[0004] The exterior appearance of acoustical panel insulation is important because such insulation is often used in visible locations, such as uses for ceiling tiles, and in modular office furniture. In particular, a smooth exterior appearance is often desired. The smooth exterior appearance can be difficult to create due to the divots, pits, and holes associated with the substrate. The exterior surface may not present a smooth appearance even when a facing is applied to the substrate.

[0005] A smooth exterior appearance is particularly important in applications where a decorative fabric is used to cover the acoustical panel in the end use. A rough textured decorative fabric can cover imperfections in the underlying acoustical panel, but many decorative fabrics, particularly those used in modular office furniture, are fine textured, and require a smooth underlying panel.

[0006] In addition to the difficulty of creating a smooth exterior appearance, acoustical laminate structures can have further weaknesses in that the facing material can come loose or tear off after the insulation is installed into the final product. Problems with inadequate attachment of facing materials can occur because the assembly process involves fusing a facing onto the underlying substrate rather than using an adhesive. The use of an adhesive in conventional acoustical panel laminate structures has been avoided because of the potential for sound degradation when a non-air-permeable adhesive is used.

[0007] Conventional methods of manufacturing acoustical panel laminate structures present further difficulties. The method used to attach the facing layer to the substrate can be expensive. Further, conventional manufacturing methods do not permit the application of a facing to both sides of the substrate in an efficient manner. Further, the manufacturing process can include a step of sanding down the substrate, especially when fiberglass board is used, to create a smooth surface for attachment of the facing. The sanding step is time consuming and expensive.

[0008] Therefore, it would be advantageous to have an acoustical panel that has a smooth exterior appearance after the addition of a facing to a substrate. Further, there is a need for a method of making a laminate acoustical panel that results in a better attachment of a facing to a substrate without sacrificing the acoustical insulation properties of the laminate acoustical panel. Further still, there is a need for a method of making an acoustical panel in which a facing can be added to two sides of a substrate simultaneously. Further still, there is a need for a method of making an acoustical panel that is more efficient than conventional methods.

SUMMARY OF THE INVENTION

[0009] One embodiment of the invention relates to a method of making an acoustical panel with a smooth exterior face. The method includes the steps of providing a fiberglass substrate, providing an adhesive, and providing a flexible facing. The method further includes applying the adhesive to the substrate, heating the adhesive, and applying the facing, whereby the facing is secured to the substrate by adhesive.

[0010] Another embodiment relates to a method of making an office partition panel out of a rigid fiberglass board and a flexible fiberglass facing. The method includes the steps of applying a cold adhesive to the fiberglass board, heating the adhesive, and applying the facing to the adhesive. The fiberglass board has surface imperfections that are filled in by the adhesive resulting in a smooth exterior surface of the facing.

[0011] A further embodiment relates to an acoustical panel. The acoustical panel includes a rigid fiberglass board, an adhesive layer, and a fiberglass mat coupled to the fiberglass board by the adhesive layer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] An exemplary embodiment will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

[0013]FIG. 1 is a schematic cross-sectional view of an acoustical panel insulation laminate structure in accordance with an exemplary embodiment;

[0014]FIG. 2 is a more detailed schematic cross-sectional view of a portion of the acoustical panel insulation laminate structure illustrated in FIG. 1;

[0015]FIG. 3 depicts a method of manufacturing an acoustical panel insulation laminate structure; and

[0016]FIG. 4 is a schematic cross-sectional view of an acoustical insulation laminate structure in accordance with an exemplary embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Referring to FIG. 1, a laminate structure 10 includes a substrate 12, a facing 14, and an adhesive 16 disposed between the substrate 12 and the facing 14.

[0018] In an exemplary embodiment, the substrate 12 is a rigid fiberglass panel. An example of such a rigid fiberglass panel is WHISPERTONE™ wall board available from Johns Manville. The facing 14 can be a glass mat, such as DURA-GLASS™ 7415 Glass Fiber Mat available from Johns-Manville.

[0019] The facing 14 is affixed to the substrate 12 by the adhesive 16. To optimize the acoustical attenuation properties of the laminate structure 10, the adhesive 16 can be air permeable to allow further penetration of sound waves into the laminate structure 10, thus facilitating sound absorption. A suitable adhesive is an XR 49 Hot Melt adhesive available from Therm O Web, Inc., of Wheeling, Ill. The XR 49 Hot Melt adhesive is a member of a chemical family including polymer resin tackifier mixtures.

[0020] The use of the adhesive 16 to attach the facing 14 can be contrasted with the conventional method of attaching a fiberglass facing to a fiberglass substrate by fusing the glass mat to the substrate during the production of the laminate. The conventional method involves fusing the glass mat to the underlying fiberglass while the underlying fiberglass is still warm, allowing the glass mat to fuse into the underlying fiberglass board. However, because an adhesive is not used, the conventional laminate structure is prone to degradation over time resulting in peeling of the facing from the underlying substrate.

[0021] Referring to FIG. 2, the substrate 12 can have surface imperfections 22 such as divots, holes, grooves, cracks, etc. The imperfections 22 can result in an undesirable exterior appearance of the laminate structure 10 even after the facing 14 is applied unless steps are taken to smooth out the imperfections 22. Conventional steps include sanding the surface of the substrate 12 prior to applying the facing 14.

[0022] The present invention eliminates the necessity of sanding the substrate 12 through the use of the adhesive 16 and the process of assembling the laminate structure 10. The adhesive 16 fills in the imperfections 22 present at an interface 20 between the substrate 12 and adhesive 16. Because the adhesive 16 fills in the imperfections 22, the interface 24 between the adhesive 16 and the facing 14 is smooth. Accordingly, an exterior surface 26 of the facing 14 is also smooth, resulting in a smooth laminate structure 10.

[0023] The smooth exterior surface 26 results from the particular combination of adhesive 16 and process for applying the facing 14 to the substrate 12. The adhesive 16 must have the proper characteristics to permit the filling in of imperfections 22 while also not degrading the overall acoustical impedance of the laminate structure 10 or resulting in an inferior bond between the facing 14 and substrate 12.

[0024] Referring to FIG. 3, individual panels 40 of the substrate 12 are fed into the manufacturing process (e.g., onto a conveyor). The adhesive 16 is applied while cold to the surface of a panel 40 from an adhesive roll 42. A first cutter 44 (e.g., heated arm) cuts the adhesive 16 to fit the pane 40.

[0025] The panel 40 is then fed into one or more ovens 46, which activate the adhesive 16 and permit the adhesive 16 to fill the imperfections 22 in the panel 40. In an exemplary embodiment where the panel 40 is fiberglass and the adhesive 16 is a polymer resin tackifier mixture, the oven is heated to approximately 450° F. to activate the adhesive 16.

[0026] While the adhesive 16 is still hot, a roller 48 applies the facing 14 to the panel 40. A second cutter 50 (e.g., knife) cuts the facing 14 to the size of the panel 40. After exiting the second cutter 50, the panel 40, which is now a complete laminate structure 52, can be loaded onto a palette. The adhesive 16 cools in a matter of seconds so no wait is required prior to stacking the final product 52.

[0027] Referring to FIG. 4, in an alternative embodiment, a laminate structure 110 can have a substrate 112 with a facing 114 applied to both sides of the laminate 112. An adhesive layer 116 is used on each side of the substrate 112 to affix the facing layers 114.

[0028] The manufacturing process depicted in FIG. 3 can be changed in one of two ways to create the laminate structure 110. First, the final product 52 can be flipped over and run through the conveyor again to apply the facing 114 to the opposite side. Alternatively, the machine can be configured to apply two facing layers 114 to opposite sides of the substrate 112 simultaneously as the panels 40 proceed down the conveyor.

[0029] The laminate structure 10 is suited for use in a variety of applications where an acoustical panel is desired but a smooth exterior finish is also desired. In particular, the laminate structure 10 is suited for use in modular office furniture where a thin sheet of material is added to the exterior of the panel that will show any imperfections lying underneath. Accordingly, the problem of undesirable imperfections in the surface of acoustical panel insulation is solved without the need to resort to sanding the underlying substrate 12. Further, the use of the polymer resin tackifier mixture as the adhesive 16 permits enhanced absorption of sound by the laminate structure 10 because the adhesive 16 is air permeable.

[0030] Another advantage of using the adhesive 16 to attach the facing 14 to the substrate 12 is that the adhesive 16 adds a more consistent color to the final product 52. The color consistency is not achieved when using conventional attachment processes such as fusing the facing 14 to the substrate 12.

[0031] The manufacturing process of the present invention results in a laminate structure 10 that is not prone to separation of the facing 14 from the substrate 12 as is the case for conventional fusing processes. Accordingly, the laminate structure 10 is better suited for use in final applications where the facing 14 is exposed to wear.

[0032] The laminate structure 10 is suited for the addition of further layers such as a decorative fabric. With conventional acoustical insulation, the resultant rough exterior appearance due to the imperfections 22 in the underlying fiberglass substrate results in the imperfections 22 being visible even after the application of an additional decorative fabric layer. This is particularly the case with fine fabrics. The present invention solves this problem by presenting a smooth exterior surface 26.

[0033] The laminate structure 10 is particularly suited for use in partition panels of modular office furniture. Typically, a decorative fabric layer is used in such modular office furniture, and the furniture manufacturer desires a smooth exterior appearance for the fabric, which is possible with the laminate structure 10 in contrast with conventional fiberglass laminates, which can have a rough exterior appearance.

[0034] The laminate structure 10 is also suited for use in acoustical ceiling tile applications. The laminate structure 10 has superior sound absorption capabilities because the adhesive is air permeable, allowing penetration rather than reflection of sound, and thus enhanced absorption of sound in the laminate structure 10. The laminate structure 10 also has a smooth exterior appearance suited for ceiling tile applications where a smooth appearance is desired. One such application is where a fabric is applied to the exterior of the laminate structure 10 facing the room.

[0035] Accordingly, the custom sound panel of the present invention solves the problems set forth in the background of the invention section by having an apparatus and method that results in a better attachment of the facing 14 and the substrate 12. Further, the method of the present invention takes less time than the conventional methods because the adhesive 16 simultaneously attaches the laminate 14 and smoothes the exterior surface 26 of the laminate structure 10, removing the need for a prior sanding step. Further still, the method of the present invention allows for the surface 26 of the facing 114 to two sides of the substrate 112 simultaneously.

[0036] While several embodiments of the invention have been described, it should be apparent to those skilled in the art that what has been described is considered at present to be the preferred acoustic panel insulation structure and method of manufacture. However, in accordance with the patent statutes, changes may be made in the design without actually departing from the true scope of the invention. The following claims are intended to cover all such changes and modifications that fall within the true scope of the invention. 

What is claimed is:
 1. A method of making an acoustical panel with a smooth exterior face, comprising the steps of: providing a fiberglass substrate having a first side and a second side; providing an adhesive; providing a flexible facing, the facing having an exterior surface; applying the adhesive to the substrate; heating the adhesive; and applying the facing, whereby the facing is secured to the substrate by the adhesive.
 2. The method of claim 1, wherein the facing is a fiberglass mat.
 3. The method of claim 1, wherein the adhesive is air permeable.
 4. The method of claim 3, wherein the adhesive is a polymer resin tackifier mixture.
 5. The method of claim 1, wherein the adhesive is applied from a roll of cold adhesive.
 6. The method of claim 1, wherein the adhesive is heated after the application to the substrate.
 7. The method of claim 1, further comprising the steps of: applying a second layer of adhesive to the second side of the substrate; providing a second fiberglass facing; and applying the second fiberglass facing to the opposite side of the substrate from the first facing.
 8. The method of claim 7, wherein the second facing is applied concurrently with the application of the first facing.
 9. The method of claim 1, further comprising the step of adding a decorative fabric layer to the panel.
 10. A method of making an office partition panel out of a rigid fiberglass board and a flexible fiberglass facing, comprising the steps of: applying a cold adhesive to the fiberglass board; heating the adhesive; and applying the facing to the adhesive; wherein the fiberglass board has surface imperfections that are filled in by the adhesive resulting in a smooth exterior surface of the facing.
 11. The method of claim 10, further comprising the step of adding a fabric layer.
 12. The method of claim 10, further comprising the steps of: applying a second layer of adhesive to the fiberglass board; and applying a second facing to the second layer of adhesive.
 13. An acoustical panel, comprising: a rigid fiberglass board; an adhesive layer; and a first fiberglass mat coupled to the fiberglass board by the adhesive layer.
 14. The acoustical panel of claim 13, further comprising: imperfections in the rigid fiberglass board; wherein the adhesive fills in imperfections in the fiberglass board.
 15. The acoustical panel of claim 13, wherein the acoustical panel is used as a ceiling tile.
 16. The acoustical panel of claim 13, wherein the acoustical panel is used in a modular workstation.
 17. The acoustical panel of claim 13, wherein the adhesive is air permeable.
 18. The acoustical panel of claim 13, further comprising: a second fiberglass mat coupled to the fiberglass panel with a second layer of adhesive, wherein the second fiberglass mat is applied to the side opposing the first fiberglass mat.
 19. The acoustical panel of claim 13, wherein the adhesive is attached by a heat treatment.
 20. The acoustical panel of claim 13, further comprising: a decorative fabric disposed on the fiberglass mat. 